1. Field of the Invention
This technology relates generally to estimating surface properties of an object from a plenoptic image of the object.
2. Description of the Related Art
Photometric stereo is a technique in computer vision for estimating the surface normals and three-dimensional structure of an object by observing the reflected light under different illumination angles. In conventional photometric stereo, multiple images of the object are captured sequentially in time using different illumination conditions. The object's surface is commonly assumed to be Lambertian (i.e., a perfect diffusive reflector). In reality, many objects are not Lambertian and have some specular reflection. Estimating surface properties for a specular surface or a surface without any texture is still a challenging problem in the field of photometric stereo. Some recent techniques attempt to address the problem of specular reflection. However, a large number of image acquisitions are required. This is time-consuming, requires more complex hardware, and is difficult to apply to video (for example, for moving objects).
Thus, there is a need for better approaches to estimate surface properties of an object.